JOURNAL OF THE AMERICAN ACADEMY OF CHILD PSYCHIATRY, Volume
23, Number 1: Pages 34-38,
January 1984.

The Effects of a Pacifying Stimulus on Behavioral and
Adrenocortical
Responses to Circumcision in the Newborn

MEGAN R. GUNNAR, PH.D, ROBERT O. FISCH,
M.D., AND STEVE MALONE

Eighteen, healthy male newborns, 2-5
days old, were subjects in this study of the effects of a
pacifier on the newborn's behavioral and adrenocortical
responses to circumcision. Half of the subjects were
randomly assigned to a condition in which they were
encouraged to suck on a pacifier during circumcision,
while half served in a no pacifier, control condition.
Behavioral observations were made of 1/2 hour before,
during, and after circumcision and 30 minutes later. The
results showed that stimulating the newborn with the
pacifier reduced crying by about 40%. Reducing crying,
however, had no significant effect on adrenocortical
response. Elevations of serum cortisol predicted average
behavioral state following circumcision, whereas crying
during circumcision did not. Furthermore, there was
evidence that the neonatal adrenocortical system was
sensitive in variations in surgical procedures. The
results indicate the importance of obtaining data on both
behavioral and hormonal systems in studies of stress and
coping in human newborns.

Journal of the American Academy of
Child Psychiatry, 23; 1:34-38, 1984.

The pituitary-adrenocortical system plays a
major role in an organisms adaptation to traumatic, stressful
conditions (Mason, 1968, Selye, 1956). In animals and adult
humans, measures of adrenocortical activity have proven to be
highly sensitive indices of stress (Frankenhaeuser, 1980,
Hennessy and Levine, 1979). Recent work with non-human
primates also indicates that this neuroendocrine system is
sensitive to stressors early in development (see review by
Coe and Levine (1981); but little is known about the response
to stress in human infants, or the relationship between
adrenocortical activity and infant behavior.

Although it was once believed that in humans
the neonatal pituitatry-adrenocortical system was relatively
insensitive to stress (Gutai et al., 1972; Hillman and
Giroud, 1965), more recent work has demonstrated that
stressors, such as circumcision, will produce striking
elevations in serum cortisol during the first week of life
(Gunnar et al., 1981a; Talbert et al., 1976). Measures of
adrenocortical activity have also been shown to be correlated
with behavioral state in the newborn. Specifically,
elevations in serum cortisol have been found to correlate
with behavioral distress or crying (Anders et al., 1970; Gunnar
et al., 1981a; Tennes and
Carter, 1973). This correspondence between crying and
adrenocortical activity suggests that stimuli which
effectively reduce crying might also effectively modify the
hormonal stress response during the newborn period.

To examine this possibility, in the
following study newborn males were given pacifiers and were
encouraged to engage in non-nutritive sucking during
circumcision. The results of a previous study showed that
permitting the newborn to suck on a pacifier was effective in
reducing crying during this surgical procedure. (Gunnar et al., 1981a). However, because
being given a pacifier was not a controlled aspect of that
study, too few subjects were given pacifiers to clearly
assess the effects of reduced crying on the adrenocortical
response to circumcision. Work with non-human primate infants
has shown that contact with mother, of which nipple-contact
is an important component, not only reduces behavioral
stress, but also reduces the infant's adrenocortical response
to stressors such as disruption of the social group, capture
and handling, and rehousing in novel environments (Coe et
al., 1978; Gunnar et al., 1981b). Thus, it was possible that
stimuli which effectively reduced crying in newborns might
also modify the newborn's adrenocortical response to
circumcision.

Method

Subjects and Conditions

The subjects were 18 healthy, male,
2-5-day-old newborns. The subjects averaged 3594 g at birth,
had 1-min Apgar scores greater than 7, and were between 38
and 42 weeks gestation. Three were delivered by elective
Caesarean section; the remainder were delivered vaginally.
Half the infants were randomly assigned to a pacifier
condition, in which they were encouraged to such on a
pacifier during circumcision, while half were assigned to a
no pacifier, control condition. There were no differences
between conditions on any of the subject variables.

Procedure

Parental consent. Parents of healthy
newborn males were contacted on the second day postpartum.
The purpose and procedures of the study were described and
written consent was obtained. Of the 85 males born in the
nursery during the course of this study, 46% met the
requirements for this study, and consent was obtained from
parents of 50% of those infants. Not all of these infants
were included in the sample, however, because of problems in
scheduling.

Serum Cortisol. Blood samples for
serum cortisol determination were obtained immediately before
circumcision (pre-session) and 30 min later
(post-session). Each sample was obtained from a scalp
vein within 5 min (X=124 sec) from the time the
newborn was picked up to be sampled. The samples were
immediately centrifuged and the serum separated and stored at
-20C. Cortisol was measured by radioimmunoassay using the
Amerlex cortisol RIA kit (Amershal Corporation). This assay
in highly specific to cortisol; however the values obtained
reflect some small amount of cortisone (1.6%) and
corticosterone (0.6%) activity.

Behavioral Measures. Two observers
recorded the newborn's behavior for the 1/2 hours before,
during (first to second blood sample), and following
circumcision. Before and after circumcision the newborn's
behavioral state was recorded every 30 sec using the 6-point
scale shown in Table I. Before circumcision the newborn's
behavioral state was observed in the nursery. After
circumcision the infants were observed while they were with
their mothers being fed and comforted. Estimates of
inter-observer agreement were calculated in 2 hours and 52
minutes of observation, using 20 pretest subjects. Agreement
estimates were calculated in two ways. First, estimates of
percent agreement were obtained for each behavioral state.
These averaged 85%. Next, average state scores were computed
by summing the state scores for each subject and dividing by
the number of coding intervals in the observation. The
Pearson correlation coefficient for these values was
0.99.

During circumcision, observers recorded
state 6 crying every 30 sec, as well as a combined measure of
body tension and activity scored on a 3-point scale (1 =
quiet, 2 = moderate, 3 = high). A score of 1 or quiet was
recorded when the newborn showed little or no movement during
the majority of the 30-sec coding interval, and in addition,
did not evidence rigid or tense muscle tone. A score of 3 or
high activity was recorded if the newborn strained against
the circumstraint straps, evidenced rigid muscle tone, and/or
moved his head and upper torso vigorously during the majority
of the coding interval. A score of 2 or moderate activity was
assigned for movement and body tension midway between these
two extremes. Observer agreement estimates calculated on 5
test subjects were all above 75% for these measures. It
should be noted that the behavioral state scale was not used
to score behavioral state during circumcision because
previous work indicated that newborns display a mixture of
states during this surgical procedure. Finally, in the
pacifier condition, observers also recorded sucking (1 =
none, 2 = moderate, and 3 = vigorous) every 30 sec.

Circumcision. The newborns were
circumcised between 0700 and 1900 hours on the day of
discharge. Seven physicians, including four junior residents,
performed the circumcisions using three circumcision methods.
The three methods were: (1) Plastibell1 (1 pacifier, 1 control), a procedure
involving progressive necrosis of the foreskin over several
days; (2) Standard Gomco clamp (7 pacifier, 5 control), a
procedure involving clamping the foreskin, then waiting 5 to
6 min before removing the foreskin; and modified Gomco clamp
(1 pacifier, 3 control), a procedure involving removing the
foreskin as soon as the Gomco clamp was secured. The average
duration of circumcision was 17.3 minutes (17.7 pacifier;
16.8 control) from the time the newborn was strapped to the
circumstraint board until he was taken off the board.
Immediately following circumcision the newborn was dressed,
swaddled, and put in his crib where he stayed until the
second blood sample was taken. This post-circumcision waiting
period averaged 12.7 minutes. It should be noted that the
adult diurnal rhythm in adrenocortical activity is not
present in the newborn and does not establish itself until
the second year of life (see review by Hung et al. (1978)).
Thus, the different clock times at which blood samples were
obtained could not have influenced the results.

Infants in the pacifier condition were given
the pacifier to suck on as they were being strapped to the
surgical board. An experimenter continued to stimulate them
to suck on the pacifier until the second blood sample was
taken. Infants in the control condition were not given
pacifiers, but were dressed, swaddled, and otherwise soothed
as soon as the circumcision was over. It should be noted that
circumcision involved the combination of a number of
stressors (e.g., physical restraint, tissue damage, and in
the present study, venipuncture). It was not the purpose of
this study to determine the relative contributions of each
stressor to the newborn's pituitary-adrenal or behavioral
response.

Results

Prior to circumcision, infants in the
pacifier and control conditions did not differ in either
average behavioral state (t(13)=1.63,NS)2 or serum cortisol concentration
(t(16)=0.21,NS). Before circumcision the infants were
in quiescent states (deep sleep, light sleep or drowsy),
exhibiting basal serum cortisol concentrations (X
± S.E. =6.7 ± 1.27 µg/dl). There was no
significant relationship between different behavioral states
in this quiescent range and pre-session serum cortisol levels
(Pearson r(13) = 0.006,NS).

Infants in the pacifier condition sucked
moderately to vigorously on the pacifier during 49% of the
coding intervals while they were strapped to the surgical
board, and during 63% of the intervals during the entire
period between the 2 blood samples. Stimulation with the
pacifier significantly reduced crying. Newborns in the
pacifier condition cried during only 46% of the coding
intervals while they were being circumcised, as compared to
81% of the intervals for newborns in the control condition,
t(16) = 6.95, p<0.01. Newborns in the pacifier
condition were also less active during circumcision, than
were newborns in the control condition. The percentage of
coding intervals during which moderate activity was recorded
was 26% (pacifier) versus 5% (control), t(16) = 2.87,
p<0.05. A similar difference was noted for quiet or no
activity (pacifier = 24%, control = 10%, t(16) = 2.25,
p<0.05. High activity almost always co-occurred with
crying and was not analyzed separately.

Once the circumcision was over and the
newborns were dressed, swaddled and returned to their cribs,
the behavioral differences between groups diminished. Neither
the average percentage of coding intervals spent crying
(pacifier = 19%, control = 35%, t(16) = 0.87, NS), nor the
average percentage of quiet activity (pacifier = 48%, control
= 34%, t(16) = 1.31, NS) differed significantly by condition
during the waiting period between the end of the circumcision
and post-session blood sample, when the newborns were with
their mothers being fed (pacifier = X ± = 2.23
± 0.26; control = 2.53 plus minus 0.25, t(14) =
0.83, NS).

Although behavioral differences were
observed during circumcision, these differences were not
reflected in the post-session serum cortisol values.
Post-session values averaged 24.2 ± 1.32 µg/dl
for the pacifier group and 24.7 ± 1.60 µg/dl for
the control group, t(16) = 0.24, NS. Additionally, there was
no evidence that the failure to observe an effect on
post-session serum cortisol values was a function of the
different circumcision technique employed.3

Measures of Δ-cortisol (post-session
minus pre-session values) were used to examine the
relationship between adrenocortical activity and individual
differences in behavior. Percent crying during circumcision
was not significantly related to Δ-cortisol in either
condition, pacifier r(7) = 0.25, NS. Average
behavioral state following circumcision was positively
related to Δ-cortisol for newborns in both conditions,
pacifier r(6) = 0.71, p<0.05. However, in neither
condition did crying during circumcision predict behavioral
state following circumcision, pacifier r(6) = 0.05,
NS) and control r(6) = 0.05, NS.

Finally, exploratory analyses were conducted
to examine the sensitivity of the behavioral and hormonal
measures to differences in circumcision procedures. Because
only two Plastibell circumcisions were performed, the effects
of this circumcision procedure were not analysed. Instead,
responses to two versions of the Gomco clamp procedure were
examined. Elevations in serum cortisol differed significantly
as a function of procedure, t(14) = 3.01,
p<0.01 (t calculated using the formula for small
samples and unequal Ns (Spence et al., 1954). The
modified procedure produced higher post-session cortisol
values 29.0 ± 1.47 µg/dl., N = 4), than
the standard procedure (22.6 ± 1.04 µg/dl.,
N = 12. This effect appeared to be due to procedure,
rather than how long the infant was strapped to the
circumstraint board. The correlation between post-session
serum cortisol and duration of circumcision (strapped down to
pick up) was not significant using all of the subjects in the
sample, r(16) = 0.10, NS.

Because only one infant in the pacifier
condition was circumcised using the modified procedure,
crying during circumcision was examined only for infants in
the control condition. The values for percent crying
completely overlapped and were 71, 79, and 80% for the
control subjects circumcised by the Modified Gomco procedure
and 65, 80, 83, 92, and 97% for the control subjects
circumcised by the Standard Gomco procedure. Following
circumcision, however, the modified procedure was associated
with more behavioral arousal (X = 3.38 ± 0.19),
than the standard procedure (X = 2.05 ± 0.12,
t(14) = 5.54, p<0.01 (formula for small
samples and unequal Ns (Spence et al. (1954)).

Discussion

Permitting the newborn to engage in
non-nutritive sucking significantly reduced crying and motor
activity during circumcision. It is unlikely that these
effects were due to response substitution, as newborns in the
pacifier condition cried and rejected the pacifier during
parts of the circumcision procedure. Nor were these results
solely due to stimulation of an incompatible response. While
sucking and crying were incompatible, body tension, straining
against the circumcision straps, and other signs of
distressed motor activity were not incompatible with sucking.
These data are consistent with the results of other studies
which indicate that non-nutritive sucking has a potent
calming effect on behavior during the neonatal period
(Burroughs, et al., 1978; Kessen and Leutzendorff, 1963).

Although newborns in the pacifier
condition showed less behavioral distress than newborns in
the control condition, post-session levels of serum cortisol
did not differ by condition. Newborns in both conditions
evidenced striking elevations in serum corticoids 30 min
after the onset of circumcision. The failure to
observe an effect of the pacifier condition could not be due
to group differences prior to circumcision. Pre-session serum
cortisol did not differ by condition. Nor was there evidence
that differences in surgical technique masked effects of the
soothing procedures on adrenocortical activity.

There are, however, at least three reasons
why reductions in behavioral distress may not have been
reflected in measures of the neonates'
pituitary-adrenocortical response in this study. First,
measuring serum cortisol levels 30 min after the onset of
circumcision may have been too early to detect an effect of
differences in behavioral distress. There is some evidence
that differences in the intensity of highly stressful events
may be reflected in the duration, rather than in the peak
magnitude of the adreno-corticoid response (Vernikos-Danellis
and Heybach, 1980). Similarly, Coe and Levine (1981) have
reported that manipulations which reduce the infant squirrel
monkey's behavioral reaction to maternal separation are not
reflected in serum corticoid levels at 30 min but are
apparent in levels measured 60 min after the onset of
separation. Thus it is possible that measures of serum
cortisol obtained at a later time point might have reflected
the differences in behavioral distress observed in the
Pacifier and Control conditions. However, the fact that the
30-min time point was sensitive to differences in surgical
technique make this explanation of the results less
compelling.

Second, the reduction in behavioral stress
produced by giving the newborn a pacifier may have been too
slight to result in any reduction in the newborn's
adrenocortical response. This explanation seems very
reasonable, but is difficult to reconcile with the results of
our previous study which showed a high positive correlation
between serum cortisol elevations and equally small
variations in behavioral distress (Gunnar et al., 1981a). In that study,
however, even though some of the newborns were given
pacifiers by the nursing staff, because that was not a
controlled aspect of the study, the nurses did not actively
attempt to encourage sucking once the newborn became highly
distressed. In the present study we encouraged the newborns
to suck on the pacifier throughout the circumcision. Thus in
the previous study behavioral distress may have been a more
direct expression of the amount of endogenous pain or stress
the newborn was experiencing, whereas in the present study
differences in behavioral stress were due to exogenous
stimulation with the pacifier. In short,
encouraging the newborn to suck on the pacifier may have
masked the behavioral expression of the newborn's underlying
physiological state, without calming the newborn sufficiently
to produce a change in physiological arousal. This
explanations points to the importance of obtaining both
behavioral and physiological measures in studies of stress or
coping.

Finally, it may well be that stimuli that
calm the newborn behaviorally have little effect on the
adrenocortical response when the stressor involves pain or
tissue damage. Nothing that we were
doing to help calm the newborn in any way altered the fact
that the newborn was experiencing an apparently painful event
that resulted in tissue damage. Under these circumstances
activity of the adreno- cortical system may be less affected
or unaffected by CNS activity mediating behavioral
arousal. Examining the effects of "pacifying" stimuli
on the neonates' adrenocortical response to other types of
potentially stressful stimuli should provide insights into
which stressors are more directly mediated by behavioral
arousal during the newborn period.

Even though post-session serum cortisol
values did not reflect an effect of the pacifier
manipulation, they did indicate that the neonatal
pituitary-adrenocortical system was highly sensitive to
variations in surgical procedures. Furthermore, the results
showed that measures of individual differences in post
session adrenocortical levels were capable of predicting
behavioral state following circumcision. During the 1/2 hour
following circumcision behavioral state was not a function of
whether the newborn had been given a pacifier during
circumcision, but was related to the magnitude of the
newborn's adrenocortical response to the surgery. Newborns
who showed higher elevations in serum corticoids were
behaviorally more aroused following circumcision when they
were with their mothers being fed. A closer examination of
this result suggested that is was due to differences in
surgical procedures.

Newborns who were subjected to the modified
Gomco procedure both showed greater elevations in serum
corticoids and were more behaviorally aroused following
circumcision than were newborns subjected to the standard
Gomco procedures. It is not clear why these effects were
observed, however, one explanation may be the rate at which
stressful or painful effects of the circumcision occurred. In
informal observations we noted that the newborns often showed
intense behavioral distress when the Gomco clamp was put on
and when it was taken off. While the clamp was in place
newborns in both conditions often calmed down. In the
modified Gomco procedure putting the clamp on and taking it
off occurred in a relative rapid sequence, whereas in the
standard version more than 5 min elapsed between these two
events. Work with mature organisms indicates that the
adrenocortical system responds more vigorously to stressful
events that occur at a more rapid rate (see review by
Hennessy and Levine, (1979)). These data may indicate that a
similar process plays a role in regulating adreno- cortical
activity in the human newborn. However the small sample size
involved in the comparison makes all interpretations
tentative.

Regardless of the explanation of these
findings, however, these data suggest that measures of
adrenocortical activity are sensitive to variations in
stressful events in the newborn period, and provide
information about the newborn's response to stressors that
may not be detected when only behavioral measures are
obtained. Examining both behavioral and
adrenocortical responses, thus appears to be a fruitful
avenue through which to explore address and coping processes
in the human newborn.

1
Measures of behavioral state post-circumcision were not
obtained for the two subjects circumcised using the
Plastibell technique. This decision was based on concern that
this technique might produce different physical stimulation
after surgery than that resulting from the Gomco procedure,
which might influence behavioral state. If so, it would add
noise to the data that could not be partialled out, because
only 2 subjects were circumcised by the Plastibell
technique.

2
Because of problems in scheduling, 3 subjects were not
observed prior to circumcision. When questioned, however, the
nursing staff reported that each of these newborns had been
sleeping quietly before the circumcision.

Dr. Megan R. Gunnar
is an Assistant Professor, and Steve Malone is a doctoral
candidate, both at the Institute of Child Development,
University of Minnesota. Dr. Robert O. Fisch is Professor of
Pediatrics, University of Minnesota. Reprints may be
requested from Dr. Gunnar, Institute of Child Development,
University of Minnesota, Minneapolis, MN 55455.
The authors would like
to express their appreciation to the staffs of Stations 59
and 68 at the University of Minnesota Hospital, without
whose help this research would not have been
possible.
0002-7138/84/2301-0034$02.00/0 copyright 1984 by the American
Academy of Child Psychiatry.

Citation:

Gunnar MR, Fisch RO, and Malone S. The effects of a
pacifying stimulus on behavioral and adrenocortical responses
to circumcision in the newborn. J Am Acad Child
Psychiatr 1984; 23(1):34-38.

JOURNAL OF THE AMERICAN ACADEMY OF CHILD PSYCHIATRY
Vol. 24, No. 3, May 1985, pages 364-365.

Letters:

Is Nonreligious Circumcision
Necessary?

To the Editor:

The article by Gunnar et al. (1984) is a
major contribution to the discussion of circumcision pain.
They suggest that although crying during circumcision may be
reduced about 40% by using a pacifier, the underlying stress,
as measured by adrenocortical response is not diminished.

The study does not mention the more
fundamental question: Why is it necessary to perform
nonreligious circumcision almost routinely? Every country,
with one exception, that adopted routine neonatal
nonreligious circumcision has either abandoned the practice
or markedly reduced the rate of performance. This may be
noted in the present rates - Britain, 1%; New Zealand, 8%;
and Canada and Australia, about 30%.

The stress of
circumcision should be reduced by abandoning the
practice.

Authors Reply

To the Editor:
We thank Dr. Wallerstein for his comments on our article. The
intent of our work is to understand stress factors and their effects
on the newborns, ultimately with an eye to determining the best modes
of helping the newborn to cope with stress. With regard to Dr.
Wallerstein's fundamental question, "to circumcise or not to
circumcise?" we agree. The most effective way to reduce the stress of
circumcision would be to abandon the practice.
Megan R. Gunnar, Ph.D.
Robert O. Fisch, M.D.
University of Minnesota
Minneapolis